1. Field of the Invention
The present invention relates generally to devices for engaging heavy or cumbersome loads, for example, rooftop heating, ventilating and air conditioning ("HVAC") units, and lifting the load off of a surface. More specifically, the invention relates to such devices which include wheels or casters, legs or support channels so that the load can be lifted, repositioned, lowered into place or secured to other objects.
2. Description of Prior Art
There is a plethora of prior art devices adapted to lift and reposition loads. Cranes, forktrucks, liftgates, carts, and scaffolding devices have all been used to reposition large loads. Generally, the most popular method is by the use of a crane. In almost every case, the prior art utilizes a means of gripping the load, lifting the load and repositioning the load, all supported by the framework and/or mass of the lifting device itself. For example, a crane includes a cable supported on an arm or a boom, means for connecting the cable to the load, and means for taking up or paying out cable as needed. The lifting of the load and repositioning of the load is completed by the mass and or framework of the lifting device. Cranes are often used to position large loads such as HVAC equipment on a roof. Coordination of delivery of HVAC equipment on a truck and the crane for lifting the load off of the truck can be difficult and often costly. If coordination of the two events do not coincide in time, a crane must be brought back to the site, at an added cost, to put the HVAC equipment into final position. Even helicopters have been used to position such equipment.